For success, we look to our rivers. In 1970, the year of the first Earth Day, raw sewage and sludge fouled waterways throughout Maine, rendering many little more than repositories of our waste. Corporations and municipalities screamed when ordered to reduce their pollution, and many denied there was a problem at all. Maine’s rivers are cleaner now, but the screaming and the denial have hardly subsided.

Clean Air Act legislation recently turned the environmental debate heavenward. Can the United States annually pour into the air more than 20 million tons of sulfur dioxide and 12 tons of nitrogen oxides without deleterious effects? How reparable is the wound chlorofluorocarbons slashed through our skies? And, finally, how much can we afford to clean up?

Earth Day 1990 is a pep talk, not a time of congratulation. What we’ve learned in 20 years is that our most serious environmental problems are also our most insidious. The general public did not know the earth had an ozone layer until part of it was eroded. Acid rain had time thin red spruce forests and scour nearly 1,200 lakes from the Southeast through eastern Canada before the idea of its presence trickled into our consciousness.

If Earth Day is to be observed, it should be as a reminder of what still needs to be done and that grass-roots movements have been successful in pursuit of a just cause. Citizens’ groups remain the vanguard of environmental concerns; most politicians have only recently understood the public’s empathy for the environment.

Denis Hayes, a leader of both the 1970 and 1990 Earth Days, has lost none of his enthusiasm for environmental causes and has gained a hard-earned wisdom to make things happen. “Concern for the environment, for ecology, can form a sectarian basis for deep changes in the world and the way we live. Social justice, peace, building a more sustainable world — thay all fit in the same overarching system of values,” Hayes told the Chicago Tribune recently. “We’ve studied our problems enough to take some concrete action. It’s time to move beyond rhetoric, and if we don’t, you’ll see the results at the polls.”

Michael Dukakis saw those results when George Bush used the polluted Boston Harbor in a campaign advertisement. Longtime Connecticut Sen. Lowell P. Weicker saw the results when opponent Joseph I. Lieberman displayed a record sympathetic to the environment and knocked the popular senator out of Washington, D.C. And former Senate Majority Leader Robert C. Byrd saw the results when he tried to add a bill-killing amendment to clean-air legislation shepherded by Sen. George Mitchell.

If cynicism infiltrates the 1990 version of Earth Day, it could be traced to the large number of Earth Day T-shirts, bumper stickers, handbooks, posters, refrigerator magnets and, for all we know, swizzle sticks. Mother Earth met Madison Avenue this year, and the results are nearly as omnipresent as smog in Los Angeles. But don’t be disheartened by the commercial aspects of the day: The plethora of advertising indicates a broad river of support from consumers concerned with matters that affect the earth.

That river, unfortunately, is so far only ankle deep. The number of cars and trucks on the road has increased by 78 million in the last 20 years, and the demand for electricity never has been greater. Products, if anything, are more likely to be single-use, disposable items than those used were two decades ago. As a nation, we are environmentalists in theory but avaricious consumers in habit.

Earth Day boosters observed this dismal fact and adapted their tactics accordingly. This year, every school district in the nation will receive an Earth Day curriculum, including take-home information packs. A generation is to grow up environmentally aware. The idea that educating children about the dangers of wasteful habits will keep them from acquiring those habits is not only sound, but shows that the Earth Day adherents are committed to long-term renovation of an economically driven society.

Meanwhile, the debate continues, with global warming as the latest theory to stand trial. Whatever the verdict there, empirical evidence of myriad types of pollution demands the growth of environmentalism. The 20 years since the first Earth Day was just the beginning of a movement that offers hope for a battered planet.